Metals tolerant catalytic cracking catalyst, method of manufacture and use thereof

Abstract

A catalytic cracking catalyst and process which tolerates high levels of vanadium and coke precursors in the feed is disclosed. A zeolite in an alumina free binder or coating, preferably silica, is used as the cracking catalyst. RE-USY in silica is especially preferred as it has a low affinity for vanadium, low coking characteristics and high stability. Preferably a vanadium getter additive is present as separate particles to act as a vanadium sink. The catalyst and process may be used in fluidized bed catalytic cracking (FCC) or in moving bed catalytic cracking units. A method of making a coated catalyst, by adding a layer of an alumina free material to a core of alumina containing cracking catalyst is also disclosed.

We claim: 
     
       1. A catalytic cracking process for the cracking of a heavy, vanadium containing oil to lighter more valuable products over a circulating inventory of cracking catalyst having cracking activity and affinity for vanadium characterized by use of a circulating inventory of catalyst comprising zeolite cracking catalyst coated with a coating consisting essentially of silica or in a binder consisting essential of silica and separate getter additive with reduced cracking activity as compared to the cracking catalyst, and having a greater affinity for vanadium than the cracking catalyst. 
     
     
       2. The process of claim 1 further characterized in that the zeolite catalyst comprises 5 to 40 wt % RE-USY in a binder of SiO 2 . 
     
     
       3. The process of claim 1 further characterized the zeolite cracking catalyst comprises an alumina containing material coated with silica. 
     
     
       4. The process of claim 1 further characterized in that a mixture of zeolite catalyst and separate particles of a vanadium getter additive are used, and the mixture comprises 10 to 50 wt % vanadium getter additive. 
     
     
       5. The process of claim 4 wherein the getter additive is selected from the group of separate particles of Al 2  O 3 , MgO, activated carbon, coke, clay, and bauxite. 
     
     
       6. The process of claim 1 further characterized in that the catalytic cracking process is a fluidized catalytic cracking process. 
     
     
       7. The process of claim 1 further characterized in that the catalytic cracking process is a moving bed catalytic cracking process. 
     
     
       8. The process of claim 1 wherein the zeolite cracking catalyst comprises 1 to 25 wt % RE-USY in a silica binder. 
     
     
       9. The process of claim 1 further characterized in that the catalyst has an average particle diameter of 10-100 microns. 
     
     
       10. The process of claim 1 further characterized in that the catalyst is in the form of an extrudate of 0.1-10 mm.